Gripper mechanism for printing-presses



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A. '0. CAMPBELL.

GRIPPER MECHANISM FOR PRINTING PRESSBS.

No; 257,129., Patented Apr. 25, 1882.

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A. O. CAMPBELL.

I GRIPPER MECHANISM 110R PRINTING PRESSES- No. 257,129. Patented Apr.25, 1882.

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UNITED STATES PATENT OFFICE,

ANDREW C. CAMPBELL, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE CAMPBELL PRINTING PRESS AND MANUFACTURING COMPANY, OF

NEW YORK.

GRIPPER MECHANISM FOR PRINTING=PRESSES.

SPECIFICATION forming part of Letters Patent No. 257,129, dated April 25, 1882,

I Application filed April 20, 1881. (Model-l To all whom, tt may concern Be it known that 1, ANDREW O. CAMPBELL, of Bridgeport, in the county of Fairfield and State of Connecticut, have invented a new and useful Improvement in Gripper Mechanism for Printing-Presses, which improvement is fully set forth and illustrated in the following specification and accompanying drawings.

This invention relates to that class of print ing-presses known as cylinder-presses, in which the impression-cylinder makes two revolutions to each impression, and in which the sheet isheld at its leading edge against the impression-cylinder or its coveringby a series of grippers attached to a rock-shaft journaled in the ends of the cylinder and occupying a gap or opening in its circumference. In many such presses the gripper rock-shaft is operated by a slotted tumbler-cam secured to one end of the rock-shaft, the slot in which cam alternately engages either fixed or movable studs, according as the cylinder makes one or more revolutions to each impressiomby which engagement the rock-shaft is oscillated, and thus opens and closes the grippers. The slotted tumbler-cam, however, is held fast in either position, corresponding respectively to either open or closed grippers by means of a rod and coiled spring, thc'rod being jointed to said 0 cam and stepped in thelend of the cylinder,

whereby the pressure of said spring transmitted to the cam retains it immovably (unless released by hand) against a stop in one end of the cylinder in either extreme position, as

above mentioned. The, action of the spring just mentioned takes up any lost motion that the rock'shaft may have due to wear, and thus obviates any variation inthe points where the grippers should fall upon the cylinders sur- 0 face. Such an arrangement of tumbler-cam, rod, and spring is shown and described in Patent No. 100,598, granted to Andrew Campbell March 8, 1870. A serious objection, however, has arisen to this arrangement for opcrating the rock-shaft and its attached grippers, due to the fact that if before starting the press, through carelessness or ignorance the grippers 'be left open when they should be closed, or vice versa, the slotted tumbler-cam, being secured to the gripper rock-shaft, will, after the starting of the press, arrive at the first stud which should engage its slot in the wrong position to allow said stud to enter said slot, and thus, instead of the stud operating the grippers by entering said slot, tlllSlnlproper and enforced contact of cam and stud will cause the fracture of some part of the mechanism.

The object of this invention, therefore, is, while providing a more effective methodof 6o alternately opening and closing the grippers at each revolution of the cylinder in a press in which the cylinder makes two revolutions to each impression, to also prevent the liability to fracture above mentioned when the parts are misplaced by accident or otherwise. The invention consists of certain devices hereinafter particularly described, and specifi cally set forth in the claims, which direct and guide the slotted tumbler-cam and its opening and closing studs, so that said cam will automatically engage the proper stud for either opening or closing the grippers, even should the grippers before the starting of the press occupy a position thereverse of thattheyshould 7 5 occupy, and thus by means of such automatic action of the cam will all danger of breakage of parts from the causes above mentioned be avoided. The grippers therefore, whether reversed or not, as above mentioned, are ncces- 8o sarily opened and closed by the cam at the proper times, for both the cam and grippers being secured to the same rock-shaft motion in the cam will cause motion in the grippers, and vice versa. 8

In the accompanying drawings, Figure 1 is an end elevation of the cylinder and attached gripper mechanism, Fig.2, a side elevation of the cylinder, showing the attached grippers. Fig. 3 shows in two views the slotted tumblero cam, which operates the gripper rock-shaft. Fig. 4 shows in two views the governing-lever for said slotted tumbler-cam. Fig; 5 illustrates in two views one end of the cylinder, in elevation and plan, respectively, showing a double- 5 inclined cam thereon for operating the devices illustrated in Fig. 6; and Fig. 6 shows in two views the sliding studs and their attached parts, by which the tumbler-cam is operated, and thereby caused to open and close the grip pers.

1n the said figures, the letter A indicates the impression-cylinder. G and 0 indicate the ends of said cylinder, upon one of which, 0, is formed or cast a double-inclined projection or can whose inclined faces are seen at To the gripper rock-shaft B are secured the grippers g, in the usual manner, as is also thereon secured the gripper 'tumblercam B, slotted as shown in the drawings, and having formed thereon two inclined or curved surfaces or wings,B B so curved that they shall each form a portion of a circle concentric with the periphery of the cylinder A in either of the cams extreme or limited positions.

Upon the back of the tumbler-cam B, or on itssideadjoiningthe cylinderendO,are formed two wings, B and B, at right angles, or nearly so, to the slot on the front side of the cam. Said cam is also provided with aroller, B, running upon a pin on the back of the cam The lever L is pivoted at L to the cylinder end 0. The free end of the lever L embraces a rod, 1", which carries the coiled spring S, and at its lower end is held in a step, S formed on the cylinder end 0, against which step the lower end of said spring reacts.

Upon the upper face of the lever L are formed twocurved surfaces. The one oflarger radius, L engages with the roller B, and the one of smaller radius, L engages with the wings B and B At the extremities of the curve L are formed two depressions, L and L corresponding in form to the roller R, and above the depression L is secured a plate, L, actingslightly as a spring to hold the roller Bin the depression L and partly as a limit to the movement of said roller. The upper half or cap of one of the bearings of the cylinder-journals is extended into a bracket, 1), which carries two sliding pins or studs, 1) 19. On said bracket is formed a web, to, to whichis secureda stud, p Said web terminates in two hubs or half round beari1igs,p p which serve as guides for the sliding studs 19 1). To said studs are attached the ends of the lcverp which oscillates upon the pivot-stud p Said ends have formed thereon oval-shaped projections 12 p", which enter notches cut into the sliding studs pp for the purpose.

Under the lever p and surroundingthe stud 11 is acoiled spring, S, one end reacting upon the head of the pivot-stud p and the other upon the under side ofsaid lever.

In the face of the lever 12 are inserted two plugs, 12 19 of wood or other substance capable of offering sufficient frictional resistance .to the oscillation of the lever p by hearing against the face of the web w, under the pressure exerted by the spring S. Said resistance counteracts the tendency in the lever to rebound when left in either position by the action of the inclines or curved surfaces A A on the end of the cylinder (1, as hereinafter explained.

The complete operation of this gripper mechanism is as follows: Starting with the grippers closed upon the cylinder, as shown by the position of the gripper tumbler-cam B in full lines in Fig. 1, and the cylinder Arotating in the direction of the arrow, the stud p (having just closed the grippers) will be in position of nearest approach to the cylinder A and the stud 1) will be withdrawn into its bearing and be most remote from the cylinder A. Butthe study, in order to clear the tumbler B, should at this time be drawn into its hearing f, and the stndp, should be out toward the cylinder A, ready to engage the slotof the tumbler B. As such, however, will not be their respective positions at this time, but exactly the reverse, the inclined surface B engages the end of the stud 1) before the arrival of the tumbler B atthat point of its travel at which the stud 11 should enter its slot, and thus forces the stud 1) back into its bearingaway from the cylinder A, and in so doing, through its connection with thelever 19 it causes the stud p to move out toward the cylinder A, and thus to be in position to engage the slot of the tumbler B upon its arrival at that point. Continuing the rotation of the cylinder A, the stud 19 opens the grippers by causing the rock-shaft B, and with it the attached grippers, to oscillate in the same direction as the cylinder itself is moving by reason of said stud 1) entering and leaving the slot of the tumbler B. The roller R during this time moves upon the curved surface L of the lever L, and the wing B leaves the curved surface L the roller R at the termination of this action entering the depression L when the wing B is brought into position upon the curve L of the lever L, all as shown in dotted lines in Fig. 1. In this position the win gB androllerB,through the action of the spring S upon the lever L, serve to limit the rotation of the rock-shaft B and hold the grippers in the open position. Continuing the rotation of the cylinder A, the tumbler B is nowin position to engage the stud p for again closing the grippers at its next passage. The stud 1), however, still remains withdrawn. But the incline A of the inclined projection upon the cylinder end C being situated in advance of the tumbler B, and at such radial distance upon the said cylinder end as to correspond with the position of the stud 1), causes the stud 19, before the arrival of the tumbler B at the proper point to engage the stud p, to be pushed back into its bearing 19 and awayfrom the cylinder vA, and thus also the stud pis brought out into position to engage the tumbler B upon its arrival, thereby again c'losing the grippers and again bringing the tumbler B into the position shown in full lines in Fig. 1.

bearin u 70H the curve L of lever L and the With the tumbler Bin the last position, the wing B roller R, lying in the depression L and under the plate L, serve to limit the rotation of the rock-shaft B and hold the grippers in the closed position. Starting again to perform a rotation of the cylinder in the same direction, if for any purpose the grippers should have been opened by hand and erroneouslyleft open, the tumbler B will clear the studp, now withdrawn, and, continuing the rotation, the tumbler B then engages the stud 12 again and closes the grippers, thus placing them in the correct position, as at first described. Starting a rotation after the stud 1) had opened the grippers--supposin g them to have been at this point erroneously closed and so left-the incline A first pushes the stud 11 into its bearin g, protruding the stud 1) toward the cylinder A, and thus would leave said studs in the wrong position to correct the error upon next encountering the tumbler B. The incline B however, again restores said studs, and the stud 19 engages the slot of the tumbler B to open the grippers, bringing everything into the proper position for alternately opening and closing the grippers at each revolution of the cylinder. In turning the cylinder A backward the operation of the parts is to first open the grippers, if closed, and to leave them open for any number of succeeding backward revolutions.

Ido not broadly claim aslotted tumbler-cam engaging with either fixed or movable studs, nor any arrangement of parts whereby the effort of a spring is caused to press the gripper rock-shaft firmly against one side of its bearing when the line of effort of a spring is directed between a fixed stop upon the cylinders end and the center of the gripper rock-shaft,

as such arrangements of parts have been long in use and are fully described in the abovementioned patent to Andrew Campbell; but

As of my invention, I claim- 1. In a cylinder printing-press, in combination with a cylinder provided with a double-inclined cam on one end and with a gripper rock-shaft carryinga slotted tum bler-cam having inclined side surfaces, a pair of sliding studs secured to a bearing or frame of the cylinder and connected by an oscillating lever, as described, and operated thereby and by said inclined cam, and operating and operated by said tumbler-cam, whereby the slot in said cam is so directed as to automatically engage said studs at the proper times for opening and closing the grippers, and breakage due to accidental displacement of the grippers prevented, substantially as and for the purposes set forth.

2. In a gripper mechanism of a cylinder printing-press, a governing-lever, L, provided with curved surfaces L L and depressions L U, and an adjusting-spring for the same, in combination with a slotted tumbler-cam, B, carrying the wings B B and the roller It, all mounted on or carried by the impression-cylinder, substantially as and for the purposes set forth.

3. In the gripper mechanism of a cylinder printing-press, and secured to a rigid framework or support, a pair of sliding or reciprocating studs, 11 p, in combination with an oscillatinglever, 19 provided with friction-blocks p 12 substantially as and for the purposes set forth.

ANDREW O. CAMPBELL. Vitnesses:

FREDERICK A. BROWER, L. M. SLADE. 

